Crome-complexing azomethine dyes

ABSTRACT

An improved method for producing 1:1 chrome-complexed azomethine dyes. Essentially, the method involves chrome-complexing an axomethine dye with a chroming reagent prepared by dehydrating a chrome-containing compound in the presence of a dipolar solvent.

United States Patent [1 1 Bader et a1.

[ Dec. 30, 1975 CHROME-COMPLEXING AZOMETHINE DYES Inventors: Henry Bader, Newton Center, Mass; Edwin G. Jahngen, Jr., Burlington, Vt.

Assignee: Polaroid Corporation, Cambridge,

Mass.

Filed: July 19, 1971 Appl. No.: 164,103

Related U.S. Application Data Continuation-impart of Ser. No. 47,174, June 17,

1970, abandoned.

US. Cl 260/438.5 R; 96/29; 96/93 Int. Cl. C07F 11/00 Field of Search 260/438.5 R, 429 C References Cited UNITED STATES PATENTS Schmidt et a1. 260/429 C 2,753,344 7/1956 Schmidt et al. 260/438.5 R X 3,398,170 8/1968 Cyba 260/438.5 R 3,597,200 8/1971 ldelson 260/438.5 R

OTHER PUBLICATIONS Rollinson et al., Inorganic Chemistry, Vol., No. 2, pp. 281-285 (1962).

Primary Examiner-1-Ielen M. S. Sneed Attorney, Agent, or FirmJ0hn P. Morley 57 ABSTRACT 31 Claims, No Drawings 3,929,848 1 a 2 CHROMECOMPLEXING AZOMETHINE DYES thoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, pentoxy, 3-methylbutoxy, hexoxy or octoxy while u and m are each positive integers from 1-2.

CROSS REFERENCE To RELATED Azomethine dyes of Formula A are prepared by re- APPUCATIONS 5 acting an ortho-hydroxy benzaldehyde with an o- This application is a continuation-in-part of ,applicahydroxynitro-aniline as follows:

(alkoxy) CH0 2 n' A OH HO DYE 0F FORMULA A tion Ser. No. 47,174 filed June 17, 1970 now aban- The ortho-hydroxy benzaldehydes employed in the doned. above reaction can be conveniently prepared by initially reacting phloroglucinol (1,3,5-trihydroxyben- BACKGROUND OF THE INVENTION zene) with an alkanol to provide the desired dialkoxy Part 1. The Field of the Invention phenol as follows:

OH alkoxy alkanol alkoxy OH OH (II) g This invention relates to 1:1 chrome-complexed 30 An especially preferred method for preparing the interazomethine dyes and 1:1 chrome-complexed azomemediate dialkoxy phenol is disclosed in commonly asthine dye dedevelopers, and more particularly, to an signed copending application Ser. No. 24,005 of Henry improved method for preparing such dyes and dye Bader and Edwin G. Jahngen, Jr., filed Mar. 30, 1970, developers. now US. Pat. No. 3,770,833. In accordance with the Part 2. Description of the Prior Art method disclosed there, high yields of dialkoxy phenol The commonly assigned, copending application of intermediate can be obtained by refluxing phloroglu- Elbert M. Idelson, Ser. No. 830,499, filed June 4, 1969 cinol with the appropriate alcohol in the presence of an now US. Pat. No. 3,597,200, relates to 111 Chr m azeotropic media and a strong acid. The strong acids complexed azomethine dyes and their use in phot are those having a negative Hammett acidity function graphic products, processes and compositions of the H value as measured in a five molar aqueous solution type described and claimed in US. Pat. No. 2,983,606 and include perchloric, fluoboric and hexafluorophosto Howard G. Rogers. phoric acids.

A180, commonly assigned, copending pp i n f In accordance with the present state of the art, the Paul S. Huyffer and Arthur B- GO intermediate dialkoxyphenol is reacted with Vilsmeier 830,480, filed June 4, 1969 now abandoned, relates to reagent, e.g., dimethyl formamide-phosphoryl chloride a particular novel class of 1:1 chrome-complexed (or phosgene) to produce the desired ortho-hydroxy azomethine dyes and more particularly to complexes of benzaldehyde as follows:

(alkoxy) (alkoxy) POCl (alkoxy) HCON (CH (alkoxy) CH0 3 2 OH OH III yellow azomethine dyes of the formula: As previously stated, an ortho-hydroxy benzaldehyde (alkoxy) Q-CH NQ (NO l OH OH FORMULA A wherein the alkoxy moiety contains from l-8 carbon is reacted with an amine as in the foregoing reaction I atoms to provide an alkoxy moiety which can be meto provide the azomethine dye of Formula A.

It has heretofore been suggested that chelatable As will beappreciated from the above, the chromeazomethine dyes can be chrome-complexed by reacting complexing of azomethine dyes of Formula A provides azomethine dyesof Formula A with a chrome-containtwo distinct 1:1 chrome-complexed azomethine dye products which are designated as Intermediate B and 5 Intermediate C. Intermediate B is a species which is cationic in nature; while Intermediate C is a species which is substantially neutral. In the synthesis presently ing compound, e.g., an inorganic chromic salt such as chromic chloride. In the synthesis known to the art, the reaction is conducted in a protic solvent such as methanol and proceeds as follows:

U NBANHQWEMMEZH employed in the art,ie.g., reaction (IV), Intermediate gand-developer, e.g., a B-hydroxy-a,B-unsaturated car- C, the neutral species, is the predominant product. I bonyl ligand containing a dihydroxyphenyl silver halide As is disclosed in the aforementioned copending developing, substituent or a protected derivative applications, l:l chrome-complxed azomethine dyes, thereof to form 121 chrome-complexed azomethine dye e.g,- Intermediates B and C, can be reacted with a li- 5 developers conforming to the following formulae:

Cr OH 2 4 H 1 Y- (R) C-(ICR FORMULA D (alkox -cn N (NO \O O I ll R c (I: c R1 Y FORMULA E (alkoxy) CH N (N0 (alkoxy) m wherein the alkoxy moiety comprises 1-8 carbon atoms am n f h neu r l In rm di C in h 1:1 and preferably l-4; m and n areas definedbefore; R chrome-complex'ed products of Reaction IV. The presand R each are lower alkyl, lower alkoxyalkyl, lower ent invention is addressed to the above discussed outfluoroalkyl, lower alkylamine, phenyl or phenylamino; standing problems in the art and provides a process for R is hydrogen, lower alkyl or phenyl; R is lower alkyl, producing lzl chrome-complexed azomethine dyes and hydroxy or hydrogen; R is lower alkylene, phenylene dye developers of improved quality in increased yields or a phenylamino radical; R is lower alkylene; Y is a and at accelerated reaction rates.

radical comprising a paradrhydroxyphenyl silver halide SUMMARY OF THE INVENTION developer substituent; X represents the atoms. necessary to complete a five or six member aliphatic ring or The present invention essentially involves the step of a benzene ring; and n is a positive integer from l2. chrome-complexing an azomethine dye with a chrom- The alkyl moieties of the above-mentioned substituing reagent which is prepared by dehydrating a ents preferably contain l-4 carbon atoms. chrome-containing compound in the presence of a The most preferred l:l c-hrome-complexed azomedipolar solvent. By chrome-complexing the azomethine thine dye developers within the above formulae are dyes in the presence of the chrome reagents of the those of the formula: present invention, unexpectedly higher yields of 1 )m H N @(NO o o 2 o 0 OH FORMULA H wherein the alkoxy moieties comprise l-4 carbon chrome-complexed azomethine dyes are obtained at atoms, m is 2, n is l and the alkylene moiety contains accelerated reaction rates. Moreover, the predominant 1-4 carbon atoms, i.e., methylene, ethylene, propylene, chrome-complexed product obtained in accordance isopropylene, butylene or isobutylene. with the process of the present invention is the afore- The above-discussed state of the art synthesis of both mentioned cationic species, i.e., Intermediate B, which, the l:l chromium-complexed azomethine dyes and l:l as previously described, conforms to the following forchrome-complexed azomethine dye developers is not mula:

(album -Q CH N 3 (NO o 0 EM as commercially attractive as desired. For example, in The predominance of the cationic specie, i.e., Interthe chrome-complexing of the azomethine dyes, e.g., mediate B, in the chrome-complexed azomethines pro- Reaction lV, long reaction times are involved and overduced in accordance with the process of the present all yields are low. Oftentimes, reaction times of 72 invention is considered important and apparently exhours are required to obtain yields" in excess of plains the high quality of 1:1 chrome-complexed Also, the present chrome-complexed products of Reacazomethine dye developers obtained by reacting the tion IV undergo reaction with the ligand-developers to chrome-complexed products of the present invention provide 1:1 chrome-complexed azomethine dye develwith the dye developers mentioned before. This explaopers of an overall quality which could be improved. It nation is consistent with the thesis of the article entitled is presently believed that the lack of the desired quality Ligand Substitution Dynamics by H. B. Gray and C. H. of 1:1 chrome-complexed azomethine dye developers Longford in Chemical and Engineering News, Apr. 1, produced in accordance with methods heretofore 1968, to the effect that ligand reactions with metal ions known to the art is a direct result of the increased such as Cr'" are facilitated if the metal carriesaformal 9 10 charge. Accordingly, two distinct advantages are inidye of the formula:

( -P P y) (n-propoxy) CH N (n-propoxy) OH tially presented by the process of the present invention has not been successfully chrome-complexed in accoras compared to the chrome-complexing process presdance with the practice of the prior art method.

ently employed in the art. First, lzl chrome-complexed The above discussed advantages obtained in accorazomethine dyes can be obtained in increased yields dance with the practice of the present invention in the and at faster reaction rates by chrome-complexing the production of chrome-complexed azomethine dyes and azomethine dye with the chrome reagents of the preschrome-complexed azomethine dye developers as well ent invention. Secondly, the chrome-complexed as other advantages of the invention will be apparent by azomethine dyes produced in accordance with the reference to the following detailed description of the present invention undergo reaction with dye developinvention.

ers to provide high quality 1:1 chrome-complexed DETAILED DESCRIPTION OF THE INVENTION azomethine dye developers.

An additional advantage of the present invention AND PREFERRED EMBODIMENTS THEREOF involves the discovery that the chroming reagents of As stated, the present invention essentially involves the present process can be employed to chrome-comthe step of chrome-complexing an azomethine dye with plex azomethine dyes of the following formula: a chroming reagent produced by dehydrating a (alkoxy) (alkoxy) CH N (N0 alkoxy) 0H FORMULA I where alkoxy and n are as defined before, which dyes chrome-containing compound in the presence of a are described and claimed in the copending applicadipolar solvent. tions of Elbert M. ldelson and Paul S. Huyffer, Ser. No. Representative azomethine dyes which can be suit- 47,l73 filed June 17, 1970. ably employed in accordance withthe practice of the As mentioned in the Description of the Prior Art, the present invention include azomethines of the following chrome-complexed azomethine dyes produced heretoformula:

(Z0) CH N (NO R v OH FORMULA J fore were produced by chrome-complexing azomethine wherein Z is hydrogen or an alkyl radical having from dyes of Formula A with a chromic salt in the presence l-8 carbon atoms, m and n are as defined before and of protic solvents such as methanol or methyl cello- R is OH or alkoxy having l-8 carbon atoms. solve (See Reaction (IV), page 5). However, as will be When R is OH and Z is alkyl, azomethines contemdemonstrated hereinafter in Examples 3 and 4, azomeplated by this invention include azomethines of Forthine dyes of Formula I, for example, an azomethine mula A, and mention may be made of the following:

ocH

(1) (121 0 CH NI; No

OH on (2) e3 0 CH N N02 OH OH OCH CH 3 2 (11) (CH3)2CHCH2O4QCH N OH OH n cn cn (CH3) 2 No CC 2 (12) (CH3) 2CHCH2CH2O Q CH N CH Ho In addition to those mentioned above, azomethines 40 mula which as heretofore mentioned are described and which can be suitably employed to prepare chromium claimed in copending application Ser. No. 47,173:

(alkoxy) N0 (alkoxy) OH FORMULA I complexes in the practice of the present invention fur- Specific 'azomethines conforming to Formula I inther include those azomethines of the following forclude the following:

(16) CH 0 .t N a NO OCH CH(CH (c11 2CHCH2CH2O Q CH N HO OCH CH CH (CH 2 OC H N02 26) (1 11 0 Cg CH N -g OC H N02 (27) C l-I 0 i; on N g HO oc n In accordance with the practice of the present invenan unsaturated dipolar bond attached to an electron tion, the azomethine dyes of Formula J are chromedonating group and particularly those conforming to complexed with a chroming reagent produced by dehythe following formulae:

drating a chrome-containing compound in the presence 3 of a dipolar solvent.

The preferred chrome-containing compounds useful R7 .[L (N )1 in preparing the chrome reagent of the present invention are the hydrated organic and inorganic chrome salts 2f the following formula: FORMULA K rA or wherein A is a suitable anion moiety such as halogen, f T nitrate, acetate, oxalate, oxide, orthophosphate, suld N fate, sulfite and tartrate. Especially preferred comj pounds of the above formula are those wherein A is \Ru halogen, and especially chlorine.

The chroming reagents of the present invention are FORMULA L prepared by dehydrating a chrome-containing coma pound in the presence of a particular class of dipolar where R is hydrogen or alkyl, e.g., having from 1-8 solvents. Broadly, the dipolar solvents suitable in the carbon atomsyQ is carbon, phosphorus or sulfur; R practice of the present invention are those containing and R can be hydrogen, alkyl or aryl, e.g., phenyl or tuted. Especially preferred dipolar solvents conforming to the above formula are:

dimethylformamide HCN(CH;,)

dimethylacetamide CH;,CN(CH )Z diphenylformamide H- N Z-pyrrolidinone l C I o l-meth l-2- rrolidinone l C O y P) N l CH piper one N/c O l-methyl-Z-piperidone c O hexamethylphosphoramide Tr/ 3)2 mcunz Those skilled in the art will recognize that solvents of Formulae K and L denote a specific group of dipolar solvents within the generic class. The effectiveness of this specific group within the genus is considered surprising and unexpected. For example, dimethylsulfoxide is perhaps the best known dipolar solvent and is routinely used in nucleophilic displacements where it is oftentimes superior in performance to dimethylformamide. However, although a chromium-containing compound can be dehydrated in the presence of dimethylsulfoxide, nevertheless, the resulting dehydrated specie does not function as a suitable chrome-complexing reagent for azomethine dyes of the present invention. Another unexpected feature of the solvents of Formulae K and L is that they need not necessarily be 20 aprotic. For example, pyrolidinone is a suitable solvent in the practice of the present invention.

The preferred dehydration method for preparing the chrome reagents of the present invention is described in the article entitled Chromium III Amide Complex Compounds by Carl L. Rollinson and Rudolf C. White, Inorganic Chemistry, 1, 281 (1962). In accordance with the method disclosed there, a chrome-containing compound and dipolar aprotic solvent are heated together in the presence of an appropriate azeotropic medium such as benzene, toluene or cyclohexane until dehydration is complete. The chroming reagent can be recovered as a solid, such as by precipitation or evaporation of the solvent and can be stored until used in the chroming reaction. Since the chroming reagents are soluble in diverse solvents including alcohols, such solvents may be suitably employed as chrome-complexing media. However, in the preferred practice of the present invention, the soluble chroming reagents are retained in the dehydration solution and the desired azomethine dye is added directly thereto.

The chroming reagents of the present invention produced by dehydrating a chrome-containing compound in the presence of a solvent of Formulae K and L conform to the following formula:

where M is a solvent of Formulae K and L or mixtures thereof, A is an anion as defined before, and p represents an integer from 1-6 and is usually 3 or 4. It should be understood that the above formula is indicative merely of the constituents of the chroming reagent and inasmuch as the exact molecular arrangement and/or configuration is not precisely known, the formula is not limited to any particular molecular configuration. For example, fromm the theory of electrons and related considerations, the chroming reagents could conceivably have any of the following configurations or arrangements: Cr A;, M Cr A M ]A, Cr A M ]A Cr M ]A;,. Accordingly, representative molecular configurations for specific chrome reagents of the present invention are considered to be as follows:

The specific reaction conditions involved in chromecomplexing the azomethine dyes with the chroming reagents of the present invention can vary. For example, the maximum temperatures employed are obviously limited by such factors as the decomposition temperature of the azomethine dye and boiling point of any solvent employed. Keeping such limitations in mind, higher temperatures are preferred and representative temperatures are those between about 20 C. to about C. Also, superatmospheric pressures can be employed. if desired. In any event, it can be said that the specific reaction conditions, e.g., temperature and pressure, will be apparent to those skilled in the art and such reaction conditions per se accordingly comprise no part of this invention. I

The invention as well as manners of practicing same and the advantagesthereof will be more fully appreciat'ed by reference to the following non-limiting, illustrative Examples.

dried at room temperature in vacuum oven, yielding 14.8 gms. (51.8% yield) of dark-brown solid. The product' absorbed at a )t 450 mu, 6 15,070. The paper chromatography of the product showed a definite center and diffused area, a band with R, of .66 and a blue ring at the solvent front. The electrophoresis O-n-C H .No i I 3 7 2 OI-D-CBH-I N02 .4. 4 n N ca N 3 7 1 0E 01-! o g o i/ Cr\ a a cl a H2O E 0 H2O INTERMEDIATE a -n-C H N02 I n-C H o cr-r N crc1 (1r o) 1 c1 (H 0) 7 in methanol 0 0 ,.C r a H20 c1 IV H2O (Page 4) k INTERMEDIATE c 1. (DMF) showed some positive and negative species, but the major portion of the material was neutral.

EXAMPLE 2 This Example illustrates the preparation of the 1:1 chrome-complexed 2,4-di n-propoxy-benzald(2-oxy-5- nitrophenyl)imine (Formula 8) in accordance with the 40 synthesis of the present invention. The synthesis can be illustrated as follows:

A solution of 37.4 g. (0.14 m.) of CrCl 6H O in 250 ml. of N,N-dimethylformamide, and 100 ml. of benzene was stirred under reflux in a l-liter flask While water was azeotropically separated into a 20-ml:= Dean l -2( 2 )4 l U- 2. 12. in methanol.

A solution of 8.0 gms.. (0.03 m.) of chromic chloride hexahydrate and of 6.2 grns. (0.015 m.)of 2,4,6-tri-n- Stark trap. The solution changed color from green to 5 propoxybenzald(2-oxy-5mitrophenyl)imine (Formula purple. Refluxing was continued for about 2 hr. until no 21 in 250 ml. of methanol was stirred under reflux for more water came over. The solution was cooled to 60 72 hours. C: and a 501mm or 50 f The reaction mixture was cooled to room temperapropoxybenzald(2-oxy-5 mtrophenyl)immc (Formula ture and added in a steady stream to one liter of water 8) m 250 of NN'dImethYIfPTmamldC (Preheiited and 250 ml. concentrated HCl. The product was slur- On a Steam bath solullon) @q ried with 9 gms. of Celite and filtered over a 6-gm. cake St eady stream Penod wlth Surfing; The of Celite and dried at room temperature in vacuum stirred reaction mixture was kept at 60 C. for 24 hrs. Oven, yielding 5-1 Ofa dark oil, which exhibited a The reaction mixture was cooled to room tempera- A at 35 in methyl cellosolve, showed no ture and added dropwise to 8 l. of water. The 1.6 l. of absorption at 445 420 and 400 mm and Showed none conc. hydrochloric acid was added in a slow stream f the bands on paper and thin layer chromatography over a period of 30 min. with vigorous stirring. The Characteristic f the chromed dye product was filtered and washed with 2 l. of water until acid free, and dried at 60 C. in vacuum oven, yielding 67.3 g. (98.5%) ofa light-brown solid. Thin layer chro EXAMPLE 4 matography (TLC) gave a major spot at R, 0 and two I minor spots at R O. l4 and 0.98. Electrophoresis gave a The followlng Example illustrates another attempl to major positive band, a minor neutral band and a very P p the 111 m ed slight negative band. Visible absorption: pp y- -q y- P y (Formula 21) in accordance with the synthesis of Example 3, but lin 445 my. 6 15.500; using methyl cellosolve as solvent rather than metha- MeCcll 4 400 no]. a d? 6 I i i A solution of 4.0 gms. (0.015 m.) of chromic chlo- MMX "W 5 ride hexahydrate (CrCl 611 0) and of 3.8 gms. (0.007 A comparison of Examples 1 and 2 reveals that the of P -"-P P9 Y wchrome-complexing synthesis of the prior art (Example phenynlmm? m 250 1 of methyl cello' 1 provides a yield of 51.8% after 72 hours whereas the Solve was stlrre d and heated at 100 C: for 72 hours: process of the present invention (Example 2) provides The reacnon mlxlure was cooled to room temper a yield of 985% after 24 hours Also a comparison of ature and added 1n a steady stream to 500 ml. of water the electrophoresis data reveals that the product of a 2 concentrated HCl: The product was slur Example 1 is predominately neutral whereas the prod n 9 Cehte and filtered over a cake uct of Example 2 is predominately cationic. This feaof Ceh te a dned at room Ltemperature m ture is considered important and possibly accounts for 40 Oven yleklmg of an There.was no evldence the improved quality of azomethine dye developers of the deslred ml by papfir or thm'layerchmma' produced by reacting the developers with the chrometography or by Vls'ble absorpnon' i complexed products of the present invention.

EXAMPLE 5 EXAMPLE 3 The following Example illustrates an attempt to pre- This Example illustrates the preparation of the 1:1 pare the 1:1 chrome-complexed 2,4,6-tri-n-propoxchromecomplexed 2,4,6-tri-n-propoxybenzald-(2-oxyybenzald(2-oxy-5-nitrophenyl)imine (Formula 21) in 5nitrophe nyl)imine (Formula 21) in accordance with accordance with the systhesis known to the art. The the synthesis of the present invention. The synthesis synthesis can be illustrated as follows: can be illustrated as follows:

oc H -n n-C 11 0 CH N oc H n OH -9 No product INTERMEDIATE 13 C H -n 2. a o/H o I o INTERMEDIATE C (TRACE) A solution of 32.0 g. (0.12 m.) of chromic chloride reflux while water was azeotropically separated into a hexahydrate in 250 ml. of N,N-dimethylformamide, Dean Stark trap. The solution changed color from and 200 ml. of cyclohexane was stirred under reflux in 30 green to purple. Refluxing was continued overnight.

a l-liter flask while water was azeotropically separated The solution was brought to 90 C. and a solution of 2.5 into a 50 ml. Dean-Stark trap. The solution changed gms. (0.006 m.) of 2,4,6-tri-n-propoxybenzald(2-oxycolor from green to purple. Refluxing was continued 5 i h l)i i (F l 21) i 25 f N overnight. Approximately 38 ml. of water came over. dimethylacetamide (preheated on a steam bath to ef- The solution was brought to 90 C. and a solution of 25 f t l ti was dd d over one hour with stirring, g 0f i- -p p y -(2- y- The stirred reaction mixture was kept at 90 C. for six nitrophenyl)imine (Formula 21) in 125 ml. of N,N- h

dimethylfol'mamide (preheated a Steam bath to The reaction mixture was then cooled to room temeffect Solution) was added Over 1 u with stirringperature and added in a steady stream to 400 ml. of The stirred reaction mixture was kept at 90 C. for 12 40 water and 100 m]. f concentrated HQ] Th product hours. The reaction mixture was cooled to room temwas l i i h 9 f C li d fil d over a P and added in a Steady stream to 4 of Water 6-gm. cake of Celite and dried at room temperature in and 1 l. concentrated HCl. The product was filtered vacuum oven, yielding 27 (88%) f li brown and dried at room temperature under vacuum, yieldmg Solid.

28.0 g. (97.5%) of a light brown solid. Thin layer chro- 5 p r chromatography d i layer chromatogfgmatogmphy showed the major p 003 phy showed the product to be the, desired chromed and trace spots at R, 0.36, 0.56, 0.75 and 0.93. The complex Visible absorption;

electrophoresis showed the main component at the cathode, a trace material at origin and a trace at the anode (35 mm.). Visible absorption: MeCell Amax 445 ml- E 14,300; MeCell )tmax 420 ml E 3,700; MeCell MeCell )max 400 my, a 13,400.

Amax 410 my. 5 15,070; MeCell Amax 420 mp. e 15,130; MeCell Amax 450 mp. e 15,100. EXAMPLE 7 The following Example illustrates the chrome-comlexin of an azomethine d e of Formula 21 with a EXAMPLE 6 c hrom e reagent prepared by dehydrating chromic chlo- The following Example illustrates the chrome-comride hexahydrate in the presence of hexamethylphosplexing of an azomethine dye of Formula 21 with a phoramide. chrome reagent prepared by dehydrating chromic chlo- The procedures of Example 6 were followed, but ride hexahydrate in the presence of N,N-dimehexamethylphosphoramide was substituted for dimeththylacetamide. ylacetamide. After eight hours at C., a similar A solution of 3.2 gms. (0.012 m.) of chromic ch10 work-up gave 2.4 gms. (79%) of a light brown solid, ride hexahydrate in 25.0 ml. of N,N-dimethy1acetawith the same chromatographic characteristics as those mide, and 20.0 ml. of cyclohexane was stirred under described in Example 6. Visible absorption:

MeCell Amax 445 mu e 14,700; MeCell Amax 420 m e 14,700;

MeCell l\max 895 mp. e 14,600.

wherein Y is a radical comprising a p-dihydroxyphenyl silver halide developer substituent or a protected derivative thereof.

Ligands within the above formulae, including illustrative examples thereof, are'de scribed and claimed in the copending application of Elbert M. ldelson, Ser. No. 881,323; filed Dec. 1, 1969, a continuation-impart of application Ser. No. 487,054, filed Sept. 13,1965 and now abandoned. 1 I

Oftentimes, where found desirablelor expedient to do so, the developer moiety is present during the complexn-CHO ing reaction in its protected form, i.e., as a protected derivative wherein the hydroxyl groups of the developer moiety are replaced by protective groups. As examples of such protected derivatives, all of which are well known in the art, mention may be made of pdiacetoxy-phenyl, p-dibenzyloxyphenyl-p-dicathyloxyphenyl, etc., the last-mentioned being particularly preferred. Where the protected derivative is employed, conversion to the desired dihydroxyphenyl silver halide developing function may be readily accomplished by well known chemical means, e.g., hydrolysis with an alkaline material such as sodium hydroxide.

EXAMPLE 8 This Example illustrates the preparation of a chromecomplexed azomethine dye developer employing a chrome-complexed azomethine dye produced by the process of the present invention (Example 5).

A solution of 2.3 g. (0.0058 In.) of a ligand of the formula:

0 O-COOCH 1 o COOC2H5 and 1.08 g. (1.39 ml 0.0058 m.) of tri-n-butylamine in 20 ml. of methanol, was added dropwise over ten minutes to a refluxing solution of 3.0 g. (0.0058 m.) of the chromed dye prepared in Example 5, in 40 ml. of methanol. After the addition, reflux was continued for-one hour. The reaction mixture, was allowed to cool to about room temperature, and then was precipitated into a solution of 500 ml. of ice water and 15 ml. of concentrated hydrochloric acid. The precipitate was washed with 500 ml. of water, and then dried for 16 hours in vacuum at room temperatureto yield a 1:1 chrome-complexed dye of the formula:

29 The resulting yellow solid weighed 4.57 g. (94.5% yield). The electrophoresis gave a major band at min., trace bands at the anode 12 mm., and 38 min., and a trace at the cathode at 31 mm. TLC showed two spots, R,= 0.03 and 0.96. Visible absorption:

MeCell Xmax 375 my. a 17,640; MeCell Amax 415 mu 6 17,400; MeCell Amax 445 my. 6 16,880.

A solution of 1.34 g. (0.0168 m.) of 50% w/w sodium hydroxide in 13 ml. of water, deaerated with nitrogen for 30 min., was added dropwise, over 20 min., to a similarly deaerated solution (with nitrogen for 30 min.) of 2.0 g. (0.0024 m.) of the above prepared chrome complex in 30 ml. of methyl cellosolve in an ice bath and with stirring. The solution was kept cold the remainder of the hour, then allowed to warm to room temperature and kept at room temperature for two hours. At this point a deaerated solution of ml. of concentrated hydrochloric acid and 75 ml. of water was added over a 10 min. period. The precipitate was filtered, washed with a 1% hydrochloric acid solution and dried at room temperature in vacuum to a constant weight to yield a high quality 1:1 chrome-complexed dye of the following formula:

The following Example illustrates the chrome-complexing of 2,4,6-tri-n-propoxybenzald(2-oxy-5-nitrophenyl)imine (Formula 21) with a chrome reagent prepared by dehydrating chromic chloride hexahydrate in the presence of 2-pyrrolidinone.

A solution of 3.2 gms. (0.012 m.) of chromic chloride hexahydrate in 25 ml. of 2-pyrrolidinone, and ml. of benzene was stirred under reflux while water was azeotropically separated into a Dean Stark trap. The solution changed color from dark green to light green. Refluxing was continued overnight. The solution was brought to 90 C. and a solution of 2.5 gms. (0.006 m.) of 2,4,6-tri-n-propoxybenzald(2-oxy-5-nitrophenyl)imine in ml. of 2-pyrrolidinone (preheated on a steam bath to effect solution) was added over one hour with stirring. The stirred reaction was kept at 90 C. for 48 hours. The reaction was cooled to room temperature and added in a stream to 200 ml. of 10% hydrochloric acid. This was extracted with 50 ml. ethyl ace- 30 tate and stripped on an evaporator at 40 C., yielding 2.1 gms. (71%) of a dark brown solid.

Paper chromatography and thin layer chromatography showed the product to be the desired chrome complex. Visible absorption:

MeCell )tmax 445 mu; MeCell )tmax 419 mu; MeCell kmax 395 mu.

Liganding of this solid showed the desired blocked metallized yellow dye developer via paper chromatography and thin layer chromatography.

EXAMPLE 10 The following Example illustrates the chrome-complexing of 2,4,6-tri-n-propoxybenzald(2-oxy-5-nitrophenyl)imine (Formula 21) with a chrome reagent prepared by dehydrating chromic chloride hexahydrate in the presence of N,N-diethyl methylsulfinamide.

A solution'of 3.2 g. (0.012 m.) of chromic chloride hexahydrate in 25 ml. of N, N-diethyl methylsufinamide and 20 ml. of benzene was stirred under reflux while water was azeotropically separated into a Dean-Stark trap. The solution changed color from dark green to purple. Refluxing was continued overnight. The solul on tion was brought to C. and a solution of 2.5 g. (0.006 m.) of 2,4,6-tri-n-propoxybenzald(2-oxy-5- nitrophenyl)imine in 2.5 ml. of N,N-diethyl methylsulfinamide (preheated on a steam bath to effect solution) was added over one hour with stirring. The stirred reaction was kept at 90 C. for 72 hours. The reaction was cooled to room temperature and added in a stream to 200 ml. of 10% hydrochloric acid. The resulting mixture was extracted with 50 ml. of ethyl acetate and the extract evaporated on a rotor evaporator at 40 C yielding 2.3 g. (98%) of a dark oil.

Paper chromatography and thin-layer chromatography showed the product to be the desired chrome complex. Visible absorption:

MeCell Amax 400 m MeCell hmax 420 mu; MeCell Amax 445 mp..

Liganding of this oil showed the desired blocked metallized yellow dye developer via paper chromatography and thin-layer chromatography.

The following Examples 1 1 and 12 illustrate an especially preferred embodiment of the practice of the present invention wherein a ligand developer of the formula OH ll is reacted with chrome complexed dyes of the present invention.

EXAMPLE 1 1 A solution of 5.02 g. (0.0202 moles) of the ligand developer of the above formula and 4.8 ml. (0.02 mole) of tri-n-butyl amine in 80 ml. of methanol was added over 20 mins. to a refluxing solution of 10.26 g. (0.02 mole) of the chromed dye prepared as in Example 5. The mixture was kept for 1.5 hrs. at reflux, then cooled to room temperature and precipitated into 1.0 l. of 5% hydrochloric acid. The product was filtered and dried at 40C. in vacuo. The dry MYDD weighed l3.3 g. (96.5% yield). Ce Titration: 95.8%k 410 m;;., e 19,040; A 440 m;.:., e 18,200.

The metallized yellow dye developer produced corresponded to the following formula EXAMPLE 12 A solution of 5.3 g. (0.02 mole) of chromium chlo- 55 ride hexahydrate, in ml. of N,N-dimethylformamide and 200 ml. of benzene, was stirred under reflux in a 500-ml. flask, while water was azeotropically separated into a 25-ml. Dean-Stark trap. Refluxing was continued for six hours; then 200 ml. of n-propanol was added, and the benzene was distilled over until the pot temperature reached 95C. The 2,4,6tri-n-propoxybenzald- (2-oxy-5-nitrophenyl) imine (Formula 21) (8.3 g., 0.02 mole) was added as a solid, and the mixture held at 95C. for 12 hrs. After cooling to 65C., a solution of 65 5.25 g. (0.021 mole) of the ligand developer used in Example 11 and 4.8 ml. (0.02 mole) of tri-n-butylamine in ml. of n-propanol was added. The reaction mixture was stirred at C. for two hours, then cooled to room temperature. The resulting solution was precipitated into 2 l. of 5% hydrochloric acid, filtered, and dried, yielding 13.7 g. (99.5% yield) of the metallized yellow dye developer of the formula shown in Example 1 1.

As shown in the foregoing Examples, in one aspect of the practice of the present invention, the chrome-containing compound is dehydrated in the presence of a dipolar solvent and the azomethine dye is directly added to the chroming reagent after dehydration. As mentioned before, the chrome reagent can be recovered after dehydration such as by precipitation or evaporation, and stored for prolonged periods of time before being used in the chrome-complexing reaction. A specific advantage of this aspect of the invention is that it permits the use of less expensive solvents such as alcohols as chrome-complexing reaction media. Also, mixtures of alcohols and dipolar solvents can be suitably employed as chrome-complexing solvent media. The following Example illustrates the use of a chroming reagent which had been recovered as a solid after dehydration and subsequently employed as a chrome-complexing reagent in an alcohol solvent medium.

EXAMPLE 13 4.19 g. (0.01 m.) of tris(N,N-dimethylacetamide) trichlorochromium (111) were added to 30 ml. of npropanol and the solution was stirred on a steam bath at a temperature of C. To this, a solution of 4.17 g. (0.01 m.) of 2,4,6-tri-n-propoxybenzald(2-oxy-5-nitrophenyl)imine in 30 ml. of n-propanol was added dropwise with stirring over one hour. The reaction was kept at 95 C. for 24 hours. The reaction was cooled to room temperature and added in a steady stream to 400 ml. of 10% hydrochloric acid. The resulting mixture was extracted with ml. of ethyl acetate and evaporated on a rotor-evaporator at 40 C., yielding 4.12 g. (81%) of a dark solid.

Thin-layer chromatography showed a major spot at R 0.00 of the desired complex; visible absorption:

MeCell Amax 445 mp; MeCell Amax 420 my; MeCell Amax 390 my.

.33 The following Example illustrates a preferred method for preparing the 2,4 ,6-tri-n-propoxybenzald( 2-oxyl5- nitrophenyl)imine employed in Examples 3-11.

EXAMPLE 14 A solution of 4.50 g. (95.6%; 0.0279 mole) of 2- amino-4-nitrophenol in 125 ml. of methanol was added at room temperature over a 1.5 hour period to a vigorously stirred solution of 8.40 g. (93.64% by v.p.c.; 0.0279 mole) of 2,4,6-tri-n-propoxybenzaldehyde in 125 ml. of methanol kept under nitrogen. Stirring was continued for 18 hours with exclusion of moisture, the mixture was filtered, and the solid washed with 60 ml. methanol, yielding 12.8 g. (92.0% theory) of redbrown crystals, m.p. 150151.5 C.

From the foregoing description and illustrative Examples, it will be seen that the present invention provides a novel, improved method for preparing the 1:1 chrome-complexed azomethine dyes of the type described and claimed in the aforementioned copending application Ser. No. 830,480.

Since certain changes may be made in the above product and process without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A process for producing a chrome-complexed azomethine dye which comprises the step of chromecomplexing an azomethine dye of the formula:

CH (NO (a lkoxy) wherein alkoxy comprises 1-8 carbon atoms.

3. A process of claim 1 wherein said azomethine dye conforms to the following formula:

(alkoxy) NO (alkoxy) y) on wherein alkoxy comprises 1-8 carbon atoms.

4. A process of claim 1 wherein said azomethine dye is:

(n-propoxy) 5. A process of claim 1 wherein said azomethine dye is:

(n-propoxy) N0 2 (n-propoxy) Q CH N g 0 8 7 u R Q N O M N (n-propoxy) 0H 6. A process of claim 1 wherein said chrome compound is a'hydrated chrome salt of the formula:

Cr A wherein A is halogen, nitrate, acetate, oxalate, oxide, orthophosphate, sulfate, sulfite and tartrate.

7. A process of claim 6 wherein said azomethine dye (n-propoxy) NO 2 said hydrated chrome salt is chromic chloride hexahydrate and said solvent is selected from the group con- (alkoxy) sisting of dimethylformamide, dimethylacetamide, -2- pyrrolidinone, l-methyl- Z-pyrrolidone, Z-piperidone, l-methyl-2-piperidone, hexamethyl-phosphoramide, 5 (alkoxy) CH N N,N-d1ethyl methylsulfinamide and mixtures of these.

8. A process of claim 6 wherein said azomethine dye is:

lO (n-propoxy) N0 (n-propoxy) CH N (n-propoxy) OH said hydrated chrome salt is chromic chloride hexahywherein alkoxy contains 1-8 carbon atoms and ll is drate and said solvent is selected from the group con- OH or alkoxy; with said chroming reagent to provide a sisting of dimethylformamide, dimethylacetamide, 2- chrome-complexed azomethine dye of the formula: pyrrolidinone, l-methyl-2-pyrrolidinone, 2-piperidone, v l-methyI-Z-piperidone, hexamethylphosphoramide, N,N-diethyl methylsulfinamide and mixtures of these. alkoxy I 2 9. A-process of claim 1 including the step of reacting the produced chrome-complexed azomethine dye with a ligand containing a p-dihydroxyphenyl substituent or alkoxy CH N protected derivative thereof to produce a 1:1 chromecomplesed azomethine dye chrome-complexed 10. A process of claim 1 including the step of react- O /0 ing the produced chrome-complexed azomethine dye with a ligand within the formulae: H o H O b. reacting said chrome complex with a ligand of the 0 i 0 formula: H-i'L-R 40 R T 1 OH Y ii H i Q m-'i)' u V J (j-Rn to form a 1:1 chrome complex of the formula:

and

alkoxy H 2 2 f L alkoxy CH N wherein R and R each are lower alkyl, loweralkoxyal- O o kyl, lower fluoroalkyl, lower alkylamino, phenyl or OH phenylamino; R is hydrogen, lower alkyl or phenyl; R 2

is lower alkyl, hydroxy or hydrogen; R is lower alkylene, phenylene or phenylamino; R is lower alkylene; Y is a radical comprising a p-dihydroxyphenyl silver halide developer substituent or a hydrolyzable pr'otected derivative thereof; X represents the atoms necessary to complete a five or a six member aliphatic ring or a benzene ring; and n is a positive integer from l-2. wherem each alkyl molety contams carbon atoms 11. A process of claim 1 which comprises the steps and is the Same; is 1 or 2; X Fepresents thefltoms of; i necessary to complete a five or SlX member aliphatic ring or a benzene ring; R is lower alkylene; n is l or 2;

a. chrome-complexing an azomethine dye of the for- I Y [S a radical comprising a hydrolyzable protected mula:

p-dihydroxyphenyl silver halide developer substituent; and Y is a radical comprising a p-dihydroxyphenyl silver halide developer substituent or a hydrolyzable protected derivative thereof.

12. A process of claim 11 wherein said ligand is OCOOC H cooc H 13. A process of claim 11 wherein said ligand is a if V H c- (CH2) OH I 14. A process for chrome-complexing an azomethine dye of the formula:

wherein alkoxy contains from l-8 carbon atoms.

16. A process of claim 14 wherein said azomethine dye conforms to the following formula:

(alkoxy) W Q on N (alkoxy) OH wherein alkoxy comprises l-8 carbon atoms.

17. A process of claim 14 wherein said azomethine dye is:

(n-propoxy) (n-propoxwGcH NKj OH OH wherein each alkoxy is the same and contains 1-8 carbon atoms, R is OH or alkoxy and m and n are an integer from 1 to 2, which comprises the step of reacting said dye with a chroming reagent prepared by dehydratirg a hydrated chrome salt of the formula:

wherein A is halogen, nitrate, acetate, oxalate, oxide, orthophosphate, sulfate, sulfite and tartrate in the presence of a dipolar solvent which conforms to the formulae:

wherein R is hydrogen or alkyl having from l-8 carbon atoms; Q is carbon, phosphorus or sulfur; R and R are hydrogen, alkyl or aryl and can be the same or different; 2 is the integer l, 2 or 3; and R represents the carbon atoms necessary to complete a 5 or 6 membered ring.

15. A process of claim 14 wherein said azomethine dye conforms to the formula:

(alkoxy) 0 (alkoxy) ca OH I OH 18. A process of claim 14 wherein said azomethine dye is:

(n-propoxy) -p p yl ca N (n-propoxy) 01-1 

1. A PROCESS FOR PRODUCING A CHROME-COMPLEXED AXOME: THINED DYE WHICH COMPRISES THE STEP OF CHROME:COMPLEXING AN AZOMETHINE DYE OF THE FORMULA:
 2. A process of claim 1 wherein said azomethine dye conforms to the formula:
 3. A process of claim 1 wherein said azomethine dye conforms to the following formula:
 4. A process of claim 1 wherein said azomethine dye is:
 5. A process of claim 1 wherein said azomethine dye is:
 6. A process of claim 1 wherein said chrome compound is a hydrated chrome salt of the formula: Cr A3 wherein A is halogen, nitrate, acetate, oxalate, oxide, orthophosphate, sulfate, sulfite and tartrate.
 7. A process of claim 6 wherein said azomethine dye is:
 8. A process of claim 6 wherein said azomethine dye is:
 9. A PROCESS OF CLAIM 1 INCLUDING THE STEP OF REACTING THE PRODUCED CHROME-COMPLEXED AZOMETHINE DYE WITH A LIGAND CONTAINING A P-DRIHYDROXYP RIVATIVE THEREOF TO PRODUCE A 1:1 CHROME-COMPLESED AZOMETHINE DYE CHROME-COMPLEXED.
 10. A process of claim 1 including the step of reacting the produced chrome-complexed azomethine dye with a ligand within the formulae:
 11. A process of claim 1 which comprises the steps of: a. chrome-complexing an azomethine dye of the formula:
 12. A process of claim 11 wherein said ligand is
 13. A process of claim 11 wherein said ligand is
 14. A process for chrome-complexing an azomethine dye of the formula:
 15. A process of claim 14 wherein said azomethine dye conforms to the formula:
 16. A process of claim 14 wherein said azomethine dye conforms to the following formula:
 17. A process of claim 14 wherein said azomethine dye is:
 18. A process of claim 14 wherein said azomethine dye is:
 19. A process of claim 14 wherein said chrome salt is chromic chloride hexahydrate and said solvent is selected from the group consisting of dimethylformamide, dimethylacetamide, 2-pyrrolidinone, 1-methyl-2-pyrrolidinone, 2-piperidone, 1-methyl-2-piperidone, hexamethylphosphoramide, N,N-diethyl methylsulfinamide and mixtures of these.
 20. A process of claim 14 including the step of reacting the produced chrome-complexed azomethine dye with a ligand within the formulae:
 21. A process of claim 20 which comprises the steps of: a. reacting an azomethine dye of the formula:
 22. A process of claim 21 wherein said ligand is
 23. A process of claim 21 wherein said ligand is
 24. A process which comprises the steps of chrome-complexing an azomethine dye of the formula:
 25. A process of claim 24 wherein said chrome salt is chromic chloride hexahydrate and said solvent is selected from the group consisting of dimethylformamide, dimethylacetamide, 2-pyrrolidinone, 1-methyl-2-pyrrolidinone, 2-piperidone, 1-methyl-2-piperidone, hexamethylphosphoramide, N,N-diethyl methylsulfinamide and mixtures of these.
 26. A process of claim 24 wherein said azomethine dye conforms to the formula:
 27. A process of claim 24 wherein said azomethine dye conforms to the following formula:
 28. A process of claim 24 wherein said azomethine dye is:
 29. A process of claim 24 wherein said azomethine dye is:
 30. A pRocess of claim 24 wherein said ligand is:
 31. A process of claim 24 wherein said ligand is: 